People

Prof. Dr. Marco Keiluweit (he/him, PI)
Marco is an Associate Professor and the PI of the Soil Biogeochemistry Group in the Faculty of Geosciences and the Environment (FGSE) at the University of Lausanne (Switzerland). Since his years as a BSc student, Marco has been interested in the molecular mechanisms that underlie soil function, and its response to climate change.  He received his BSc in Geoecology fom the University of Tübingen (Germany) as well as MSc and PhD degrees in Soil Biogeochemistry from Oregon State University (USA). During his PhD, Marco worked as a Lawrence Scholar in the Isotope Signature Group at Lawrence Livermore National Laboratory (USA). After defending his dissertation in 2013, he joined the Environmental & Soil Biogeochemistry group at Stanford University (USA) as a Postdoctoral Scholar between 2014 and 2015. Marco became Assistant Professor of Soil Biogeochemistry at the University of Massachusetts-Amherst in 2016, before moving his group to UNIL in 2022.  

Dr. Floriane Jamoteau (she/her, postdoc)
Floriane joined the Soil Biogeochemistry group in April 2023 after completing her PhD thesis at CEREGE (France). Her PhD thesis focused on the characterization of soil organo-mineral associations at the micro- and nano-scale (nanoCLICs-type co-precipitates) and the monitoring of their fate after a land-use change and organic fertilization. As a post-doc, she is particularly interested in monitoring the fate of organo-mineral associations in the rhizosphere: such as their transformations, rates of formation and disruption at short and medium time scales (weekly to seasonal scale), as well as observing the underlying mechanisms through micro- and nanoscale analyses.

Dr. Emily Lacroix (she/her, postdoc) 
Emily joined the Soil Biogeochemistry group in January 2023. She received her BA in Chemistry modified with Environmental Studies from Dartmouth College (USA) and a PhD in Soil Biogeochemistry from Stanford University (USA). Emily is broadly interested in soil carbon cycling and specifically interested in how anoxic microsites, zones of oxygen depletion in otherwise oxic soils, may (or may not!) affect soil carbon cycling. Her postdoctoral work will investigate whether roots are key drivers of anoxic microsite formation and if root-associated anoxic microsites alter the fate of root-derived carbon.

Dr. Megan Foley (she/her, postdoc)
Megan joined the Soil Biogeochemistry group in November 2024. She received her PhD in Biology from Northern Arizona University (USA) where she studied environmental and evolutionary controls over microbial growth in soil. Megan is interested in how microbe-mineral interactions affect organic carbon cycling in soils. During her PhD, Megan was awarded a National Science Foundation Graduate Student Research Program fellowship and worked in the Environmental Isotope Systems Group at Lawrence Livermore National Laboratory (USA) as a Department of Energy Graduate Student Research Fellow.

Philip Gwyther (he/his, PhD student)
Philip joined the Soil Biogeochemistry group in July 2024. He became interested in microbial biochemistry during his BSc in Molecular Biology at the University of Sheffield, working on metabolic modeling and bacterial detoxification projects. He completed his MSc in Integrative Biology at the University of Lausanne, where his thesis focussed on the role of niche availability in soil inoculant persistence. As an SNSF Junior Researcher, he used deep learning to analyze the cytometric diversity of soil microbiota. In his PhD, Philip will investigate how tidal and diel cycles drive redox conditions and microbial metabolism in salt marsh soils and their subsequent impacts on carbon cycling in the system. 

Nathan A. Chin (he/him, PhD student)
Nathan joined the lab in Fall 2018 after completing his undergraduate BSc in environmental studies at Cornell University. At Cornell, Nathan completed an honors thesis looking at changes in enzyme activity in forest soils following increased nitrogen deposition and soil acidification. He is particularly interested in soil biogeochemical cycles nd how they interact with each other, particularly carbon. Branching out from his undergraduate experience, Nathan joined the Soil Biogeochemistry group to study manganese redox cycling in forest soils and how it links to organic matter decomposition. ​

Junna Frei (she/her, PhD student)
Junna received her MSc in Biology at the University of Neuchâtel specializing in Sustainable Agriculture and Chemical Ecology. During her thesis on biorecovery of phosphorus from digested sewage sludge using basidiomycetes, she developed a strong interest in mycology, particularly in the ability of fungi to recover nutrients from their substrate. At UNIL, she is involved in a research experiment aimed at determining the impact of changes in rainfall intensity on the dynamics of mineral-organic associations in the rhizosphere. She is particularly interested in investigating how fungi affect mineral-organic associations.

Dr. Xu Fang (he/him, postdoc)
Xu joined the Soil Biogeochemistry group in April 2024. He obtained his doctorate in August 2022 and did his first postdoc at ETH Zürich, where he investigated soil management strategies and the underlying biogeochemistry of decreasing As and Cd accumulation in rice. He is fascinated by the plant-mineral-microbe interactions in the rhizosphere of wetland plants where root-released oxygen meets the otherwise anoxic water-saturated soil matrix, dictating the fate of nutrients, toxins, and organic carbon in such soils. His postdoctoral research at UNIL will address how does organic carbon decomposition in the coastal marsh rhizosphere responds to tidal variations.

Bouke Bentvelsen (she/her, PhD student)
Bouke joined the Soil Biogeochemistry group as a PhD student in November 2024. She holds a degree in Biomedical Sciences from the University of Amsterdam. Initially involved in a collaborative project connecting cancer research and developmental biology, she found herself more interested in the environment than in humans. It led her to environmental microbiology, where, as an SNSF researcher, she worked a project aimed to identify and classify soil bacterial species using live cell imaging data. Now, in her PhD, she wants to better understand organic matter dynamics in soil, with a specific focus on the role of soil bacteria. Soil microbial communities affect both carbon retention and release in the soil, with bacterial necromass playing a significant role in carbon persistence. Her research focuses on the microenvironments controlling necromass formation and persistence.